Joss Whedon ’87, writer, director and executive producer of such popular TV shows as “Buffy the Vampire Slayer,” “Angel,” “Firefly,” and the new series “Dollhouse,” will give the May 30 keynote address for the seventh annual Shasha Seminar for Human Concerns. The unique seminar scheduled for May 29 through 31 will focus on “Defining American Culture: How Movies and TV Get Made.” Jeanine Basinger, the Corwin-Fuller Professor of Film Studies, Chair of the Film Studies Department, and curator of the Cinema Archives will be the facilitator for this seminar. Other presenters include successful Wesleyan alumni who work as film and…